Controller for oscillation generators



March 31. 192K.

1,531,378 G. H. CLARK CONTROLLER FOR OSCILLATION GENERATORS Filed Feb. 16, 1921 2 Sheets-Sheet 1 mrzwrafi GEOEGE H. CLERK By hzls fliio ncy March 31. 1925.

s. CLARK CONTROLLER FOR OSGILLATION GEIBRATORS 2 Sheets-Shut? Filed Feb. 16, 1 521 ///////7/////////// I I I I I.

Patented Mar. 31, 1925.

UNITED STATES PATENT OFFICE.

GEORGE E. CLARK,

OF BROOKLYN, NEW YORK, ASSIGNOR TO RADIO CORPORATION OF AMERICA, .4! CORPORATION OF DELAWARE.

CONTROLLER FOR OSCILLATION GENERATORS.

Application filed February 18, 1921. Serial No, 445,299.

To all 11:72am it may canoe 1%.

Be it known that I, GEORGE H. Cmnn, a citizen of the United States and a residentof Brooklyn, New York, have invented certain new and useful Improvements in Controllers for Oscillation Generators, of which the tollowing is a specification, accompanied by drawings.

This invention relates to controllers for generators of oscillations such as are genera-tors, for producing electromagnetic waves.

Prior to my invention the arc generators or converters required a plurality of manual operations for putting the are into service. These steps had to be taken in the proper sequence and great care was therefore necessary in putting the are into operation for the transmission of signals.

An object of my invention is to provide controlling apparatus that will enable the attendant to start the are in proper sequence and perform all the necessary operations without giving any further thought to the manipulation than to move a controller handle.

Another object of my invention is to provide a controller that will enable the operator to putthe are out of service in proper sequence and leave it in proper condition for starting. Further objects will be referred to in the following description, reference being had to the drawings in which Fig. 1 illustrates the improved controller containing my improvements.

Fig. 2 is aview of certain parts of the controller, with unessential parts removed.

3 illustrates an automatic arc-striker attachment of a modification.

In the drawing, the are 1 adapted to be connected to an antenna 2 is fed with direct current from agenerator 3 furnished with power from a motor 45. The are converter may have the usual copper anode 5 and car-- bon cathode 6, the feeding of which is controlled by an electric motor 7. The shuntseries field 8 is provided, as usual, to influence the are to aid i the produ t on f os fl:

lations. Hydrogen-containing gas is fed to the arc and this gas may be produced by feeding water, alcohol, kerosene or other ap propriate'fluid from reservoir 9 intothe hot arc chamber.

In order to prevent excessive heating: of the arc converter, cooling-coils 10 are provided in which may circulate water or other cooling fluid by means of a suitable pump 11 and tank 12. A

lVith the foregoing general description of the converter system detailed reference to the controller circuits will now be given. In the position shown in Fig. 1 the various parts are in the off-position. and the converter is out of service. hen the converter is to be put into operation the operator grasps the controller handle 13 and rotate" the attached disk 14 and contact arm 15 in clockwise direction, as shown on the drawings. lVhen the controller is moved into position A the cam portion 16 of the insulated, disk 15L engages the switch arm 17 and closes the circuit to the pump motor 18. This circuit may be traced "from the main 19 through wire 20 to switch arm 17. wire 21, motor 18, wire 2-9., back to main 2 3. This starts the flow of water through the cooling channels to absorb the excess heat produced in the arc converter.

The reason I prefer to start motor at this initial step in the operation is because the controller will be left in this position quite often when receiving signals. This will enable the water to be circulated through the cooling chambers and thus absorb the heat so that the arc will be ready for efficient operation when transmission is resumed and reception interrupted.

In the next step or position B. the cam 16 raises switch arm 24. and connects main 19 to the junction point 2". This closes the circuit of the hydrogen control magnet- 26, the carbon rotating motor 7 and the relay magnet, or solenoid, 27'. The three circuits referred to may be traced from the point to the common junction point 28, which is connected to main 23 by wire 29.

the coolin gr provide an explosive mixture with the cxygen'contained in it. The carbon rotating motor is arranged to be connected at this point and it isunnecessary for it to be in operation prior to this time. 'Anct-her reason for not putting the motor into operation in position A is on account of that position being the onein which. the controller will be left quite frequently when receiving signals. In such position the motor shouldbe shut down inorder to eliminate the noise incident to its operation. The relay key' 51 is connected in circuit at position B in order to enable the operator to test it out prior to the arc being struck to determine if it is in working order. Relay keys frequently stickand by testing the relay out before the arc is struckthe oper ator will be enabled to put the relay in order before proceeding further.

In the next step of the operation the controller is moved into position C. The cam 16 in this position operates switch and connects the solenoid of the main line contactor 32 to the common junction point 28. In this circuit isalso connected the magnet 33 of the contactor 34 for the constant fluxcoil 85 of the flux control of the are. If for any reason the motor 4 should not be up to speed, magnet 36, which isconnected across the terminals of the motor, would not be energized and the circuit closed by switch 30 would be open 'atswitch 37. This latter switch then is a safety device to prevent'the main contact oi '32 being closed when the motor-generator set is not up to speed, as will happen if the motor generator set had ,been just previously started and had not properly accelerated at the time switch arm 30 was moved in closed position. This automatic switch 37 can be attached in any other way to the motor or generator so as to remain open until the motor or generator is up to voltage or speed.

The switch 32 having been closed, the generator potential is applied to the arc electrodes but prior'to this time the electrodes have been entirely free of any-high potential so that the electrodes could have been handledby the operator for cleaning purposes without receiving a shock. ,The constant field is alsoapplied at this time by coil -having beenenergized through the closing of switch 34.

Prior to position B the contact arm 15 has engaged no contacts but in position C it engages contact-38 but in theclockwise direction of the controller arm this contact closure at this time has no-operative effect.

T he purpose of this contact will be described later. in position D the contact arm 15 engages contact strip 39 and connects the field rheostat 40 in series with the field 41 of the generator 3. This gives minimum voltage on the are for starting on account of the field resistance being in circuit and turtheron account of resistance 42 being in the main arc circuit. As contact arm 15, and of course the attached cam 14,- are moved towards position E switch arm 43 is brought to closedposition by cam 16 before the arm 15 breaks contact with strip 39. This closes the arc extinguishing switch 44 in the main antenna circuit.

Everythin'g is now in readiness for striking the arc and the operator pushes forward on the electrode feeding means shown schematically as a handle 45 (Fig. 2) to bring the electrodes together and strike the arc; For. clearness of illustration this is omitted from-Fig. 1. When handle45 is pushed forward, the rod 45' enga es rod 51' and compresses springs 46 and 4 and this moves electrode 6 until it engages electrode 5. When pressure is released, rod 45 is forced back until collar 48 engages support 49" as shown. a square fit with the end of rod 45 to prevent its turning when handle 48 is rotated.

Spring 47 cooperates with collar 51 to hold the rod 51 as shown in Fig. 1. Prior to this time the arc could not be struck because a projection 46 on the striking bar 45 would have engaged the side of the cam member 14. When the switch arm 43 has reached position D, a slot 48 in the disk member 14 moves opposite the projection 46 and the operator can then strike the arc. The electrodes can be separated to the desired distance for the generation of continuous oscillations by manipulation of handle 48 secured to rod 49 threaded into support 50. As rod 49' is fed back or forward the carbon-holding bar 51' slides The support 49" has through bevel gear 52' and'thus moves the carbon electrodefi. The rod 51 is splined or square, as shown, in the bevel 52, to enable the electrode being rotated by the motor 7 (Fig. 1 The are has now been formed between the electrodes 5 and 6 and current flows from the generator through the series coil 8 to furnish the field for the arc.

Cam member 14 can-again be rotated as lug 46 is now back in normal position. Further movement of switch arm 15 and cam member16 intoposition Fmerely cuts out a further section of a field Y resistance and when-the arm takesupposition'G an additional section, of the resistance is cut out.

'As the arm is moved still further cam 14 engages switch 49 and closes the circuit of magnet 50 which short circuits the resist-y ance 42 in the main arc circuit. This applies additional voltage to the arc. Further movemei'it of a controller member merely cuts out the additional sections of the field resistance to increase the voltage of the generator. The arm 15 can be moved backward and forward to get the desired'arc voltage and if it should be necessary to have further reduction of generator field current than can be secured with arm 15 in position H, this can be obtained by manipulation of hand rheosiat 60 shown schematically in the generator field circuit of Fig. 1. This permits of the reduction of the generator field current without opening switch 49 by backward rotation of cam 16. Rheostat 60 can also be used to secure fine adjustments of field current in various positions of the main controller.

After the converter is in operation the operator can do the desired signalling by manipulation of signalling key 51 which operates the relay 27 to open circuit and short circuit the antenna inductance 52, or by otherwisechanging the constants of the antenna system in accordance with the various known ways of producing signals with oscillating arc. systems. In the reverse rotation of the controller when the arc converter is being shut down, the steps performed will be merely a reversal of those already described and willbe fully understood without further reference thereto. However, it should be pointed out that as the controller arm 15 is rotated counter-clockwise switch arm 43 is released by the cam member 16 and magnet 44' is tie-energized. This opens the antenna circuit and extinguishes the arc as it has no oscillating circuit to. keep it in operation. It has formerly been the practice to open the arc circuit by opening the main power supply switch, but I have found that if this arc extinguishing switch 44 be located between the arc and the antenna in ductance there is practically no arcing at the switch contacts as distinguished from the very destructive are encountered with previous switches located in different portions of the power circuit. The location of the contact switch in this position is therefore a very important improvement. It should also be pointed out that arm 15 en gaged contact 38 prior to leaving contact 39. Further rotation breaks contact between the arm 15 and contact 39 and the self inductive discharge of field 41 takes place through resistance 53 and there is therefore minimum sparking on interrupting the field. An. additional reason for there being minimum sparking at this time is on account of the arc having been extinguished by the opening of the contactor 44 in the antenna and thus eliminating the field flux due to the series coil 54: of the cumulative compound wound generator 3.

In the reverse movement of the controller it is important to point out that the are extinguisher contact opens first and extinguishes the arc. A resistance is shunted around the generator field and then the field circuit is opened. Line contactor 1161i opens, there being no current in the line to cause spark ng. There are therefore three safety provisions for insuring that the arc circuit is open when the controller is in the oif-position. The are extinguishing contactor rt is the first one to cause the arc to extinguish. If this switch sticks and fails to open the field circuit the generator is open, taking the voltage off of the arc. If this should fail to open through a grounded wire or other defect the main line switch 0 will open the arc circuit. It will therefore be seen that I have provided a controlling device with high factor of safety both as to the operator and as to the mechanism itself.

The field resistance taps connecting the controller contacts with resistance 4-0. are preferably made adjustable so that the desired amount of resistance canhe included between taps and when once these are set the controller will always produce the same amount of increase in generator voltage applied to the arc providing hand rheostat 60 is in normal position. Therefore a pointer .55 (Fig. 1) may move over a scale and thus indicate the voltage impressed on the arc. This scale may also further indicate the various positions of the controller.

It is desirable to have an automatic arcstriker connected with the cont-roller and in Fig. 3 I have illustrated a modifiedarrangement to accomplish this purpose. For simplification the essential parts only are shown and these are illustrated more or less schematically to further aid in the understand ing of the invention. It will be understood that the circuit arrangement of Fig. 1 will be used in connection with the controller of Fig. 3. 6

Referring to Fig. 3, when cam member 1-1 is rotated the pin 61 secured thereto engages cam member 62 and causes it to move with it in clockwise direction. The striker rod 63 slides on the concentric surface 64 of the cam and no longitudinal movement of the rod takes place until the switch arm 43 is engaged by cam 16 as in Fig. 1. Just at this time projection'65 on auxiliary cam member 62 forces striker rod 63 and forces it to the left (in Fig. 3) until it engages carbon holder rod 51 (as in Fig. 2). This strikes the are as previously described. Contact of the arc electrode is for the moment only.as the rod 63 rides on projection 65 and releases to normal position through influence of spring 66 which engages collar 67 on the rod. Further rotation of cam member 14 performs the operation already described in connection with Fig. 1 and in addition the cam surface 68' of auxiliary cam 62 permits the rod 63 to move gradually to the right under influence of spring 66 and thus-auto- -matically increase the arc length. The arc length may 'be further adjusted by hand wheel 69 to initially compensate for burning of the carbon electrode or lior other reason.

IVhen the converter is in operation the controller be rotated backwards to reduce the field current without changing the arc length. This is accomplished by means of the slot 70 in cam. member 62. The triotion of rod 53 against cam memberGZ holds the latter stationary until pin 61 engages either one end or the other of slot 62. This slot and pin connection also permits the main line switch 32 to open before the electrodes are brought together on the reverse movement ofthe controller, thus preventing any current flowing through the arc electrodes from the generator when the electrodes momentarily touch on the ai'c extinguishing movement of the controller.

The auxiliary hand rheostat .60 previously referred to, whose sliding contact arm is normally set so as to include one half the resistance of the rheostat, is provided so that compensation for voltage changes due to speed variation, power-line voltage change and other causes may be manually accomplished. a

It will be obvious that my controller need not be connected to the various circuits in the exact way indicated as this has been shown'by' way of example only. Instead of controlling the voltage of the generator by 7 cutting in and out sections of the field re- 'sistance the'controller may operateon re sistance in any other circuit or in any other Way control the arcinputs. Various other modifications and embodiments of my invention may be made without departing from the spirit of the invention.

Having described the invention, what I claim is: V r

1. In radio signalling systems, an arc converter, means for supplying fluid to the are, means for striking the arc and means to prevent the are being struck before said fluid is supplied. V

' 2. In radio signalling systems,- an arc\ converter, .means for supplying varying amounts of power to said are and means to preclude the striking of the arcwith full power supply. I

v3. In radio signalling systems, an arc converter, means for supplying fluid to the are, a source of variablepower supply for the arc, means for striking the arc, and means to render said striking means operas tive only after the said fluid is supplied and only under reducedpower supply.

4. In radio signalling systems, an antenna, an arc converter connected therewith,

a source of power supply for the arc, means for disconnecting said are converter from the disconnection of the power supply from the converter until after the converter is.

disconnected from the antenna.

7 5; In radio signalling systems, an an-r tenna, an arc converter adapted to be connected thereto, a source of power supply 7 tor the converter and means for precluding the connecting of said source to the con verter before the converter is connected to the antenna whereby the circuits will bein condition for generation of continuous oscillations when the arc is struck.

6. In radio signalling systems having a plurality oi? controlling circuits, an arc converter, means for strikingflthe arc, and means for preventing the operation of said striking means until the desired control circuits are closed.

7. In radio signalling systems, an antenna system, an are connected therewith, and means for opening the circuit of theante'nna system substantially at the junction point of said antenna system and are for interrupting the arc.

' 10. In radio signalling systems, an antenna, an are connected therewith, ZL'SWltCll between said are and antenna, a source of electromotive force, a switch for connecting said arc to said source,striking means for said are and mechanism to prevent the op eration of said striking mechanism until said switches are closed. 11.In radio signalling systems, an antenna,-an are connected therewith, a generator and means to prevent the connecting of said generator to said are until the volt age of the generator attains a predetermined value. 7 V

12. The combination with an antenna system, an arc, a signalling relay of means for connecting said arc to said antenna system and permitting the energization of said relay prior to the connection of the arc to said member for striking the arc and for ncreasing the arc length as sald control member is moved afterthe arc is struck.

14:. The. combination with an arc 'con-i' mechanically connected to said control member for striking the arc at a pred termined position of the control member and for in 10 creasing the length of the arc as said control member is moved after the arc is struck.

GEORGE H. CLARK. 

